Laser imaging system 100, shown in FIG. 1, typically includes a light source 108 which emits light which is focused on an imaging media 124. The light passes through imaging lens 116, and is focused on specific areas of the surface of the imaging media 124. The imaging lens 116 may comprise a single lens element or may be a compound imaging lens 116 comprising a plurality of lens elements.
Although the glass components forming imaging lens 116 are transparent, the light absorption by the lens is not zero. In cases where the light source 108 is a laser and emits high energy, the energy absorption in imaging lens 116 is significant, and it increases the temperature of the glass components, creating a thermal gradient within the imaging lens components. This temperature variation causes a change in the optical behavior due to variations in size, shape, and index of refraction. Each one of these changes or a combination of them may cause a shift in the image position, yielding a shift in imaging lens 116 focus. The change in focus introduces image artifacts on the imaged imaging media 124.